Switch control system



April 2, 1940. c. w. DALZELL SWITCH CONTROL SYSTEM Filed Aug. 12, 1939 2Sheets-Sheet l av .mw 6% N SQ mm Q v6 W w w E mfi WV mw GVV GWV c &w m mn w wsmfi} m W. mi 3w 0 Q a m g 0 mm. Wm Q 1111 ILF IL \J MN WWGNNJLIPWN K u w $9 Na W mm m w v w ma ell.

HIS ATTORNEY c. w. DALZELL' 2,195,884

SWITCH CONTROL SYSTEM Filed Aug. 12, 1939 2 Sheets-Sheet 2 April 2,1940.

DaZ eZZ- INVENTOR HIS ATTORNEY Cla ence Q. WN RN iimm -f 111111 11% MNmm mm X g mm mm mm Patented Apr. 2, 1940 UNl-TED STATES ,ATENT OFFiCE2,195,884 SWITCH ooNrRoL SYSTEM I Clarence W. Balzell, Belleville N. 3.,assignor to The Union Switch & Signal Company, Swissvale, Pa, acorporation oi lennsylvania Application August 12, 1939, Serial No.289,893

10 Claims' (Cl. 246-442 My invention relates to switch control systemsfor railway track switches, and has particular reference to improvedsystems of the class in which a selector conditions a railway trackswitch for operation by either remotely controlled power operating meansor by local manual operating means. I

In switch control systems of the above class, a selector" is provided'for a switch operating mechanism and when set in a normal positionpermits operation of the associated switch by power operating means to aposition of ccrrespondence with a polarized switch control relay whichis'controlled by a control lever located in a remote control office, andwhich selector when set in a reverse position prohibits operation bypower operating means and permits manual operation of the switch bymeans of a hand lever provided for the switch operating mechanism.

In connection with such dual control switch operating mechanisms, it isdesirable to prevent automatic restoration of the switch by the poweroperating means to its position of correspondence with the switchcontrol relay after the switch has been locally operated and theselector restored to its normal position. Thus, in the event that theswitch has been manually operated to a position out of correspondencewith the switch control relay, the restoration of the selector toitsnormal position will not cause the power operatingmeans toautomatically restore the switch to the position corresponding with therelay, with the result that movement of the switch under the wheels of atrain is-prevented in the event the switch is occupied when the selectoris restored to its normal position.

Accordingly, an object of my present invention is to provide an improvedsystem of the class described and incorporating means to insure againstautomatic restoration of the switch upon operation of the selector toits normal position after the switch has been manually operated to aposition out of correspondence with the switch control relay. l

A further object is to provide an improved system of the class describedand incorporating means eiiective when the switch has been manuallyoperated, to establish remote control of the switch upon operation of aremote switch control lever.

An additional object is to provide an improved system of the classdescribed and incorporating means providing control of a switch from a.remote point, andjwhich requires the provision of but two line wiresfrom such remote point to the location of'the switch.

A still further object is the provision of an improved system of theclass described and incorporating means providing control of a switch 5from a remote point through the provision of i normally deenergizedcontrol line wires.

Another object is to provide an improved system oi the class describedand incorporating means effective whenthe switch has been manuallyoperated, to prev'entremote control of the switch until the remotecontrol lever is moved to a position out of correspondence with theswitch control relay;

A further object is to provide an improved systemof the class describedrequiring a minimum of apparatus for effecting the above and otherimportant objects. j I

An additional object is to provide an improved system of the classdescribed and employing circuit means controlled by the remote controllever for establishing remote control of a power operating means, andwhichincorporates a circuit controlling contact operated toan openposition when the selector is moved to condition the switch for manualoperation, and which contact is restored to its normal closed positiononly after the selector is restored to its normal position and theremote control lever is moved to a position out of correspondence withthe switch control relay.

Another object is to provide an improved switch control systemforrailway trackswitches;

Other objects and advantages of my invention will be apparent from thefollowing description taken in connection with the accompanyingdrawings.

I shall describe two forms of apparatus em+ bodying my invention, andshall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view of one formof an improved switch control system embodying my invention. Fig, 2 is adiagrammatic view showing a modified form of the system shown in Fig. land also with a selector which operates a link 4.

When selector SL is in its normal position, as shown in the drawing,link 4 conditions the switch for operation by power switch operatingmeans, designated by the reference character M, and when the selector isin its reverse position, link 4 conditions the switch to operation bymanual operating means, here shown as a hand lever H.

Selector SL also controls a member 5 which rotates about a pivot 6between a normal position as shown and a reverse position. Member 5 r isadapted to engage a contact controlling memher I, pivoted about 6, tomove the latter member from its normal position as shown into a reverseposition. Member 'i in its reverse position engages a, contact member 8to move member 8 out of engagement with a contact member 9 and therebyopen a normally closed circuit controlling contact 8-9 formed by the twocontact members. Contact controlling member 1 is biased by any suitablemeans, such, for example, as a toggle l0, into its last operatedposition, so that once operated by selector SL to its reverse position,selector SL may be restored to its nor mal position but member T isretained in its reverse position by virtue of the action of toggle I6,thereby holding contact member 8 out of engagement with contact member 9until such time as member 7 is actuated against its bias into its normalposition. Contact members 8 and 9 are biased into mutual engagement withthe result that when member 7 is restored to its normal position,circuit controlling contact 8-9 also is restored to its normally closedposition by virtue of the bias of members 8 and 9.

Member I also is controlled by a reset magnet RM having an armature Hwhich at times engages contact controlling member 'I, the arrangementbeing such that when contact controllin member I is in its reverseposition and armature H in its released position, the energization ofmagnet RM and consequent operation of its armature l l to its attractedposition operates member 7 against its bias into its normal position,thereby permitting contact 89 to become closed. Preferably, the forcesexerted by selector SL and the armature of magnet RM are selected andproportioned in such manner that selector SL, when operated into itsreverse position to force contact controlling member '5 into its reverseposition, exerts a force upon member 1 which exceeds the force exertedupon member I by armature H. Selector SL in its reverse positionaccordingly holds contact controlling member I in its reverse positionagainst the energization of magnet RM, and prevents armature ll ofmagnet RM from moving to its attracted position in the event that magnetRM is energized during the interval that selector SL is in its reverseposition.

Magnet RM also is provided with a normally open contact l2-l2a whichbecomes closed only when the associated armature H is operated to itsattracted position. It can be seen that during the interval selector SLis in its reverse position, contact l2l2a of magnet RM cannot be closedif magnet RM is energized, since the associated armature l l of themagnet cannot be operated to its full attracted position, due to thefact that contact controlling member 1 (which is held in its reverseposition by selector SL) engages armature H and prevents movement of thearmature to its full attracted position.

The power switch operating means of mechanism SM,-hereinbefore referredto, is illustrated in the drawing as a switch movement of the typehaving a reversible electric motor M which comprises an armature l3 anda field winding id, but it is contemplated that other types of switchmovement, such for example, as the type provided with a pneumatic motor,may be employed if desired.

Remote control of switch mechanism SM is established by means of acontrol lever E, which may be a switch control lever of an interlockingmachine and which is generally positioned at a point remote from thelocation of switch SM. Lever E preferably is a manually operable circuitcontroller of the type operable to two extreme positions and biased toan intermediate position. As is readily apparent from an inspection ofthe drawing, lever E operates as a pole changer to supply line wires l5and i8 (which extend from the position of lever E to the location ofswitch S) with current of one polarity or another from a suitable sourceof current, such as a battery not shown in the drawing but locatedadjacent the switch control lever and having its two terminalsdesignated by the reference characters B and C. Normally, with lever Ein its mid position, the wires I5 and I6 are deenergized.

In accordance with the polarity of current supplied to wires l5 and I6,one or another ,of two switch operating relays NWR and RWR is adapted tobe controlled through the medium of a polarized switch control relay PRmechanically interlocked with a neutral relay NR in such manner thatrelay PR is permitted to reverse its polar contact only after neutralrelay NR is energized and operates its associated armature to itsenergized position.

Polarized switch control relay PR comprises, as shown, a magnet l'lhaving two windings Ila and Nb and a polarizing winding [8, which latterwinding preferably is provided with a permanently magnetized core l9.Mounted on core 19 is an armature 20, the arrangement being such thatwhen windings Ila-I'll) are supplied with current of one polarity,armature 20 is operated in a counterclockwise direction to a normalposition, that is, the position illustrated in Fig. 1, but that whencurrent of the opposite polarity is applied to windings l7allb, thearmature is then swung in a clockwise direction to a reverse position.In either event, energization of winding :8 is effected to strengthenthe permanent magnetic field and thereby increase the polarizing actionof core l9. Armature 20 of relay PR is operatively connected with a,polar contact member 2!, which is operated to a normal position whenarmature 20 is in its normal position, to close normal polar contactZD-Zl. When armature 20 is swung to its reverse position, contact member2| is swung to a corresponding reverse position and closes reverse polarcontact 2l-'23.

Neutral relay NR controls a pivoted armature 24, the lower end of whichprojects into the path of movement of a portion of armature 20 of relayPR to prevent movement of the latter armature when relay NR isdeenergized. Armature 24 of relay NR carries contact fingers 25a and 25badapted to close front contacts 262'! and 28-29, respectively, whenrelay NR is energized. Contact finger 25a also closes a back contact30-3I when relay NR is deenergized.

It should be pointed out that the polarized switch control relay usuallyis positioned adjacent its associated track switch, and hence is subjectto relatively severe jars and shocks due to railway trafiic moving overor adjacent the switch. It is readily apparent, however, that with2gl9fig88-k which. may be, traced from terminal B throughagainst andavoiding-improper operation of theswitch due to an accidental reversalof the switch.

control relay contacts. t v

The reference character J designates aswitch cirouitcontrollercomprising a movable contactmember 32 operatively connectedwith switch Sin the usual manner for movement between a normal position. (in Whichit.is. illustrated) and a reverse position.

all positionsof switch S except its fullnormal position, and also:engages another fixed contact member 34.. at. all positions or theswitch except when the switch isin its-full'reverseposie tion.

The reference character OR designates an and a stick winding 36.

sistor 31, the function of which will be made i clear presently.

is closed, relays NR, PR, OR, NWR, RWR and magnet RM are alldeenergized, motor M also is deenergized, and switch S and polar relayPR are in corresponding norinal positions.

I shall now assume that switch 5 is operated;

by-power to its reverse position. To do this,

lever E is actuated to its lower position (as viewed in the drawing) toconnect wire l5- with the B terminal of the source of current over levercontact 38-40, and to connect'wire' it with A the C terminal of thesource overlever contact Relay NR now becomes energized over" an obviouscircuit and attracts its armature out of thepath oftravel of armature 26of relay PR. The energizationof relay NR also closes front contacts26-2'| and ZB-JQ, the closing of the last mentioned contact completinganobvious. circuit for winding l8 of relay- PR, which circuitis-supplied with energy; from a local source, such as a batterypositioned adjacent the switch. The closing of front contact 25 -21 ofrelay NR completes anobvious circuitfor reset magnet RM, whereupon itsarmature H is attracted to its energized position and coin tact iii-12ais closed. This completes a circuit including the source ofcurrentlocated adjacent lever E and the line wires I5 and I6, wherebywindings lla-|'lb of relay PR are supplied with current of a polaritysuch tliat 'armaturezfl of relay-PR is operated to its reverse position.It should be noted that a resistor-43a and an asymmetrical unit 44w areconnected in par allel with winding Ila and a-resistor-43b and anasymmetrical unit MD are connected in parallel with winding lib toimprove the operation of relay PR.

Lever E may now be released, thereby interrupting the supply of energyto relays NR and PR, and relay NR releases its armature to-close back.contact 3fl.-3!', whereupon reverse operatingcrelayzRwRbecomesenergized=over-acircuit Contact member 32' of con.- troller Jengages a fixed contactmember 33 at back contact -3 I of relay NR,circuitcontrob ling;contact.8e9,.back.contact IE-45b ofrelay 9B,.reverse, polar contact, ll-23, of relay PR,

the-winding of reverse. switch. operating relay RWR and contact Sit-32.of controller J. (closed;

inrthe; normal. position of theswitch). to. termr- 1 nal C.

The energization of; reverse operating. relay RWR causes motor M tobecome energized. over. a. reverse operating circuit, which ext'endsiromterminal B through front. contact .46.-4Ga. of.

relay RWR, armature i3 ofmotor M, front con.-

tact 414la of relay RWR, field winding; IA of. -motor M and overloadwinding of'relay OR.

in parallel with resistor 3i, to terminal C. :The

polarity of energization of motor M is now such that the motor operatesswitch S to its reverse position, the circuit being maintained (unlessmo tor M becomes overloaded) until the. switch reaches its full reversepositionwherein contact 32-'34. of controller J is opened. The openingof contact 32-3l of controller J interrupts the.

previously. traced circuit of relay RWR, whereupon the relay releases toterminate operation of motor M and switch S.

Winding 35 0f relay. ORand resistor 31' are so proportioned that underordinary operating conditionsthe current division between the relaywinding and the resistor when motor M is energized is such that. theenergy level created in relay OR is insufiicient to. cause the relay tobecome picked up. However, in the event that motor M? becomes overloadedwhen operating switch S toits reverse position, as might occurif theswitch strikesan obstruction or is blocked from moving to its fullreverse position, the excessive current drawn by motor M under thelatter condition causesresistor 3's to heat up and increase itsresistance, thereby increasing thecurrent flow througlrwinding 35 and asa result the energizationof winding 35. increases to a point suchthattherelay picks up to open its back contact -451) and close-its frontcontact 45 -4541. The opening of back contact 45-451)- of relay ORinterrupts the previously traced circuit of'relay RWR and as a resultrelay RWR re leases to terminate the operation of motor M. The closingof front contact" 45-450; of relay OR connects stick' windingtfi ofrelay OR in circuitwith back-contact Bib-3i of relay NR'and circuitcontrolling contact l -hand stick'winding 35 accordingly becomes.energized to hold relay OR'picked up until contact 3- -9 is opened,oruntil relay NR becomes energized.

When the switch is in its full reverse position, or'when it is'in a midposition and relay OR is held-picked up over its stick winding. 36, theswitch may-be restored to its normal position by actuatingswitch controllever E in its upper di-:

rection (as viewedin the drawing). Wire Ifiis now connected with the Bterminal of the source of current by lever contact air-42. while wire isconnected with the C terminal by lever conof reset magnet RM closes,windings l'lai?b-of' relay PR-i'are supplied with current of a polaritysuch as to cause the relay to operate its armature to its normalposition. Lever E may now be released, thereby permitting relay NR tobecome released and close back contact 30-31 to establish a circuit,which includes circuit controlling contact 8-9 and normal polar contact21-22 of relay PR as well as contact 32-33 of controller J, for normalswitch operating relay NWR.

The energization of relay NWR causes motor M to become energized over anormal operating circuit which may be traced from terminal B throughfront contact Mia-48 of relay NWR, armature 13 of motor M, front contact49-4961. of relay NWR, field winding 14 of motor M, and overload winding35 of relay OR in parallel with resistor 31, to terminal C. The polarityof energ'ization of motor M is now such that switch S is moved to itsnormal position. When the switch reaches its full normal position,contact 32-33 of controller J opens to interrupt the circuit of relayNWR whereupon that relay releases to terminate operation of motor M andswitch S.

It should be pointed out that in the event mo- .tor M is controlled tooperate switch S to its ,relay NR becomes energized due to an operationof lever E to pick up relay NR, or until selector SL is operated to itsreverse position to open circuit controlling contact 8-9.

I shall now assume that with the apparatus 0f Fig. l in its normalcondition (as illustrated),

selector SL is moved to condition the switch for hand operation, therebyopening circuit controlling contact 8-9. Switch S may now be operated toits reverse position by means of hand lever H. If, during an operationof switch S by lever H, lever E is operated in an attempt to remotelycontrol the switch, such remote control is prevented by virtue ofcontact 8-9 which is held open by selector lever SL. Thus,althoughamovement vof lever E to either of its extreme positions will cause relayNR to become energized and thereby control reset magnet RM to itsenergized condition, selector lever SL in its reverse position iseffective to maintain contact controlling member ,1 in its reverseposition against the energization of reset magnet RM, and also iseifective to prevent the closing of front contact 12-12a of magnet RM.Accordingly, windings Ha-IIb of relay PR remain deenergized since theenergizing circuit for such windings is open at front contact 12-1211 ofmagnet RM, and as a result relay PR retains its armature in its normalposition. Then, if lever E is released to its mid position so that relayNR becomes deenergized ,and closes back contact 311-31, neither of thetwo switch operating relays NWR and RWR can become energized, since thecircuit for each of the relays is open at circuit controlling contact8-9. It follows, therefore, that the construction ,and control ofcircuit controlling contact 8-9 by selector SL prohibits remote controlof the switch during the interval the selector conditions the switch formanual operation. Also, the control of contact 12-12a of magnet RM byselector SL prohibits either relay NWR or RWR from being energized inresponse to an operation of switch lever E during the interval thatselector SL conditions the switch for operation by hand lever H.

In the event that switch S is manually operated to a position out ofcorrespondence with relay PR and the selector is restored to its normalposition, the action of contact controlling member 1 in holding circuitcontrolling contact 8-9 open functions to avoid automatic restoration ofthe switch to its position of correspondence with polar relay PR. Thatis to say, when selector SL is restored to its normal position, contactcontrolling member 1 is held in its reverse position by virtue of theaction of its toggle 10, with the result that contact 8-9 is held open.Accordingly, the circuit for normal operating relay l\WR which normallywould be established with relay NR released and relay PR in its normalposition while switch S is in its reverse position, is open at circuitcontrolling contact 8-9, and consequently automatic restoration of theswitch to its position of correspondence with relay PR is avoided.

Relay PR may be restored to control of switch mechanism SM by actuatinglever E to either of its extreme positions to cause relay NR to becomeenergized. With relay NR energized, magnet RM also becomes energized toattract its armature 11 to its energized position, thereby closing frontcontact 12-12a. and operating contact controlling member I to its normalposition to permit circuit controlling contact 8-9 to become closed.With contact 12-120. of reset magnet RM closed due to the energizationof that magnet, relay PR will be operated to its normal or its reverseposition according as lever E. is actuated to its corresponding normalor reverse position to supply wires 15 and 1G with current of normal orreverse polarity. If the position of lever E is such that relay PR isactuated to its position of correspondence with switch S, then whenlever E is released and relay NR becomes deenergized, the apparatus willremain in its position wherein switch S and relay PR are in agreement.However, if lever E is actuated to control relay PR to a position out ofcorrespondence with switch S, then when the lever is released and relayNR, becomes deenergized, switch S will be controlled to its position ofcorrespondence with relay PR, in a manner pointed out hereinbefore.

From the foregoing description, it can be seen that the apparatus ofFig. 1 permits remote control of the switch by the switch control leverwhen the selector is positioned to condition the switch for poweroperation, and that when the selector conditions the switch for manualoperation, remote control of the switch by the control lever isprohibited.

It is readily apparent that the control of circuit controlling contact8-9 is such that if the switch is manually operated to a position out ofcorrespondence with the switch control relay, automatic restoration ofthe switch to its position of correspondence is avoided when theselector is restored to its position conditioning the switch for poweroperation. It is also apparent that contact 8-9 is controlled to restorethe apparatus for remote control whenever the switch control lever isactuated after the restoration of selector SL to its normal position. Itfollows, therefore, that apparatus embodying my invention provides anovel and improved switch control system for dual-control switchmovements, and requires a minimum of apparatus to at times prohibitpower operation of the switch and automatic restoration of the switch toits position of correspondence with the switch control relay.

In Fig, 1, the control linewires 15 and 16 are normally deenergizedsince lever E is biased to its mid position where the wires aredisconnected from the source of current located at the lever, and theapparatus is arranged to operate during the. relatively short intervalof time the lever is actuated to connect the source of current to thecontrol wires. Because of the fact that the apparatus of Fig. l iscaused to operate on a relatively short impulse of current, suchapparatus is particularly well adapted for use in systems of the typeknown as Coded centralized trafi'ic control systems. In: such systems,control code impulses are supplied to normally deenergized line wires toeffect operation of a switch or other trafilc controlling apparatuspositioned at aremote point. When the apparatus of Fig. l is used in asystem of the type mentioned,- the control impulse may be supplied byany of the usual and well-known code transmitting devices.

' In Fig. 2, a modification of the system shown in Fig. l. is shownwherein the control line wires are normally. connected in an opencircuit with the source of current. Lever El of Fig. 2 is of the usualtype movable between a normal and a reverse position and remains in itslast operated position. The remainder of the apparatus of Fig, 2 issubstantially similar to the apparatus of Fig. l previously described,except that two additional polar contact members 50 and 5| arecontrolled by relay PR to form normal polar contacts 5ll-52 and 5!-53and reverse polar contacts EtL-M and 5l55, which are interposed inenergizing circuits shortly to be pointedout for relay NR. Also,overload relay ORl of Fig. 2 is provided with a toggle controlledarmature 58 which is operated from a normal into an operated positionupon energization of overload winding 35 of relay OR! by current ofoverload magnitude, and

is retained in its operated position by virtue of the action of itsassociated toggle 5l' until a reset winding 53' provided for relay ORlis energized to attract it's own armature 59 into engagement witharmature 56 to restore the latter armature to its normal position.Armature 56 of winding 35 controls a normally closed contact 6ll50a insuch manner as to open that contact whenever armature 55 is in itsoperated position. Armature 59 of winding 58 controls a contact lit-6mto an open or closed position according as winding 58 is deenergi'zed orenergized. The parts of the relay are arranged to permit armature 59 ofwinding 58 to operate into or from its deenergized andenergizedpositions without effecting operation of armature 55 of winding35, when the latter armature is in its normal position.

Lever El of Fig. 2 in its normal position N connects terminal B withwire l5 and terminal C with wire l6, and in its reverse position, connects terminal B with wire l6 and terminal C with wire l5.

' Wires l5 and ll; of Fig. 2, although'constantly' connected by lever Elto the source of current are normally deenergized by virtue of the factthat the circuit across the wires normally is open,

through contact 38 l2 of lever El, wire l6, normal'polar contact 525fiof relay PR, normal polar contact Ell-53 of relay PR, and the winding ofrelayNR to terminal 0. The energization of relayNR closes front contact28-439 to energize winding 18 of relay PR, and front contact 26-27 ofrelay NR also becomes closed tocomplete a circuit which includes winding58 of relay OR! in series with the winding of magnet RM, therebyenergizing reset winding 58 of relay ORI (which causes contact Gi-lilato close) and reset magnet RM (which causes contact l2'l2a to close). Inaddition, contact 52-53 of relay NR is closed by contact finger 25c ofrelay NR to complete a circuit for windings lla--l'lb of relay PR, whichcircuit extends from wire [6 through windings lid-I'll) of relay PR,contact E2Hia of reset magnet RM, contact 5la6l of winding 58 of relayORl, and contact 53- -62 of relay NR to wire l5. The polarity ofenergization of windings l'la -l'lh oi? relay PR is such that the relayoperates its armature to its reverse position, thereby opening itsnormal con tacts 525il and 5l56 to interrupt the previously tracedcircuit of relay NRso that relay NR releases. With relay NR released,winding 58 of relay ORl, reset winding RM, winding l8 of relay PR andwindings i'lolllb of relay PR "all become deenergized. Also, when backconfor relay PR across the two control wires l5 and l6. i

To restore relay PR and switch S to-their respective normal positions,lever B l is moved to its normal position, thereby energizing relay NRover a circuit extending from'terrninal B through contact 38 lt of leverEl, wire l5, reverse polar contact 55-5l of relay PR, reverse polarcontact 52--54 of relay PR. and the winding of relay NR ing 58 of relayORE, reset magnet R'i/l, winding ll! of relay PR and magnet ll of relayPR are all energizedjand the polarity of energization of magnet l! isnow such that armature of relay PR is swung to its normal position,thereby open ing its reverse polar contacts 55-5l and 59-54 to interruptthe circuit of relay NR. When relay NRreleases and closes back contactfill-3i normal switch operating relay N'WR becomes energized to controlthe switch S to its normal position.

It should 'benoted that whenever lever'El is moved to a position out ofcorrespondence with polar relay PR, the movement of lever El to suchposition closesa circuit across wires 55 and l B which energizes relayNR. Relay NR, accordingly, is energized only whenever lever El is movedto a position out of agreement with relay PR.

In the event that switch S is manually operated to a position out ofcorrespondence with switch control relay PR and the selector is restoredto its normal position,.circuit controlling contact 8 9 is held in itsopen position by virtue of the toggle biased contact controlling memberl. Thus, when'selector SL is restored to its normal position, circuitcontrolling contact t-9 being open prevents either relay NWR or RWR'fromto terminal C. With relay NR energized, windbeing energized, and therebyavoids automatic restoration of the switch to its position ofcorrespondence with relay PR after a manual operation of the switch.

In the event that circuit controlling contact 89 is held open by thetoggle biased contact controlling member I, the contact is restored toits normal position to thereby establish remote control of switch Swhenever lever El is operated to its position out of correspondence withrelay PR and relay NR becomes energized. Under the above conditions, theenergization of relay NR causes reset magnet RM to become energized andactuate its armature ll into its attracted position to operate contactcontrolling member 1 against the action of toggle l9 into its normalposition. Circuit controlling contact 8-9 now becomes closed. Thus, forexample, if switch S is manually operated to its position out ofcorrespondence with lever El and relay PR, contact 89 becomes closedonly when lever E! is moved to its position of correspondence withswitch S and causes relay PR to assume its position of correspondencewith switch S. In the event that the switch is manually operated and isleft at its position of correspondence with lever El and relay PR whenselector SL is restored to its normal position, the operation of leverEl to its position out of correspondence with relay PR causes contact8-9 to become closed, and also causes relay PR and switch S to beoperated to their respective positions of correspondence with lever El.It follows from the foregoing that remote control of the switch isestablished only when circuit controlling contact 3-43 is caused tobecome closed when the switch. control lever is moved to a position outof correspondence with the polarized switch control relay.

It should be pointed out that whenever lever El is moved to a position.out of correspondence with relay PR during the interval that selector SLconditions the switch for manual operation, contact 8-4) is held open byselector SL against the energization of reset magnet RM to prohibitremote control at this time. Also, since contact l2.l2a of reset magnetRM is held open under the above conditions, relay PR is not operated toits position of correspondence with lever El, but remains at itsposition out of correspondence with lever El until such time selector SLis restored to its normal position. Then, however, when selector SL isrestored to its normal position, contact l2--l2a of reset magnet RMcloses and relay PR operates to its position of correspondence withlever El. If, now. switch S is in correspondence with lever El, nooperation of the switch is effected, but the switch is out ofcorrespondence with lever El, then relay PR controls the switchoperating relays NWR and RWR to cause the operation of switch S to itsposition of correspondence with lever El.

In the event that overload relay OR! operates its main armature 56 toits operated position due to current of overload ma nitude being drawnby motor M. it can be seen that armature 55 is restored to its normalposition whenever lever El is moved to its position out ofcorrespondence with relay PR to cause the energization of relay NR andconsequent energization of reset magnet 58 of relay ORl.

An advantage of the apparatus of Fig. 2 is that automatic restoration ofthe switch to its position of correspondence with its polarized switchcontrol relay is avoided by means of a circuit controlling contact 8-9,which is so constructed and controlled as to require the xninimum ofapparatus to provide the above protection in switch control systems fora dual-control switch mechanism.

Although I have herein shown and described only two forms of improvedswitch control srs' terns embodying my invention, it is understood thatvarious changes and modifications may be made therein within the scopeof the appended claims without departing from the spirit and scope of myinvention.

Having thus described my invention, what I claim is:

l. The combination with a railway track switch having a two-positionselector effective in but one position to condition the switch for poweroperation, oi a circuit controlling contact operativcly associated withthe selector and operated from a normally closed position to an openposition when the selector is moved out of its said one position, saidcontact having means for maintaining the contact in its open positionwhen said selector is restored to its said one position, a switch.control lever having normal and reverse extreme positions, poweroperating means, means controlled by said lever when operated to anextreme position and including said circuit controlling contact in itsclosed position for controlling said power operating means to move theswitch to a position of correspondence with said lever, and meanscontrolled by said lever and effective when and only when said selectoris in its said one position for restoring said circuit controllingcontact to its normal position upon movement of said lever.

2. The combination with a railway track switch having a two-positionselector effective in but one position to condition the switch for poweroperation, of a circuit controlling contact operatively associated withthe selector and operated from a normally closed position to an openposition when the selector is moved out of its said one position, saidcontact having means for maintaining the contact in its open positionwhen said selector is restored to its said one position, a switchcontrol lever having normal and reverse extreme positions, a polarizedswitch control relay, circuit means controlled by said lever andeffective when and only when said selector is in its said one positionfor operating said relay to a position of correspondence with theextreme position of said lever, power operating means, means controlledby said relay and including said circuit controlling contact in itsclosed position for controlling said power operating means to operatethe switch to a position of correspondence with said relay, and meanscontrolled by said lever and efiective when and only when said selectoris in its said one position for restoring said circuit controllingcontact to its normally closed position upon movement of said lever.

3. The combination with a railway track switch having a two-positionselector effective in but one position to condition the switch for poweroperation, of a circuit controlling contact operatively associated withthe selector and operated from a normally closed position to an openposition when the selector is moved out of its said one position, saidcontact having means for maintaining the contact in its open positionwhen said selector is restored to its said one position, a switchcontrol lever having normal and reverse extreme positions and biased toan open intermediate position, a polarized switch control relay, circuitmeans effective when and only when onenesssaidzselector" is in its said'one. position for con:-

' trolling saidrrelay to a position otfcorrespondor operating means;circuit meanscontrolled by once with the extreme position'of said lever,powsaid switch control relay and including'said circuit controlilng.contact :in' its closed position forcontrolling said poweroperatingmeans'to operate the switchto its position of correspondencenormalposition upon operation of said lever to either of its extremepositions. a

4. The combination. witharailway trackswitch having a two-position.selector efiective in but one position to condition the switch forpower" operation, of a circuit controlling contact operativelyassociated with theselector and operated from a normally closed positiontoan open position when the selector is moved out of itssaid oneposition, said contact having means for maintaining the contact in itsopen position whensaid selector is restoredto its said one position, a

switch control lever havingnormal and reverse extreme positions andbiased to an intermediate position, two normally deenergized controlline circuit controlling contact in its normally closed position forcontrolling said'power operating means to operate the switch to aposition of 'cor- I I respondence with said relay, and. means controlledby saidlever and efi'ective'when and only when said selector is in itssaid one position for restoring said circuit controlling contact to itsnormally'closed position upon operation of said lever to eitherextreme'p'osition;

5. The combination with a railway track switch having atwo positi'onselector efiective in but one position to condition the switch for poweroperation, of a circuit controlling contact opera tively associated withthe selector and operated 1 from a normally closed position to an openposition when the selector is moved out of its said one position, saidcontact having means for maintaining the contact in its open positionwhen said selector is restored to its said one position, a

switch control lever having normal and reverse position, two normallydeenerglzed control line' extreme positions and biased to anintermediate wires, a source of current connected by said lever to saidcontrol wires to supply current of normal or reverse polarity to suchwires according as said lever is in its respective normal or reverseextreme position, power operating means for operating said switch.control. means selectively controlled in accordance with the polarity ofenergization of said control wires for controlling the operation of saidpower operating means to cause said switch to be moved to a position ofcorrespondence with said lever, means controlled by said circuitcontrolling contact when held opened by said selector being out of itssaid one position for preventing said control means from responding tothe said selector is. iniits said'one position for re-.

polarity is supplied to said control wires; when.

storing said circuit controlling-contact to its normally closedposition.

6; The combination with a railway track switch having a two-positionselector effective in but tion when the selectoris moved out of itssaid.

one position, said contact having means for maintaining the contact inits open position when said selector is restored. to its said oneposition,. a

switch control lever having normal and reverseextreme'positions. andbiased to an'intermediate position, two normally deenergized controlline wires, a source of current connected by said lever tozsaid. controlwires to. supply current of normal or reverse; polarity to such wires.according as said lever is in its respective normal or reverse extreme:position, a neutral relay connectedin circuit'with said controlwires, apolarized switch control relay mechanically interlocked with saidneutral relay whereby saidpolarized relay is permitted to reverse itspolar contacts only when said neutral relay isenergized, means effectivewhen said neutral relay is energizedfor connectingsai'dipolarized relayin circuit with said control. wiresprovided that said selector is in itssaid one position, power operating means .for operating.theswitch,.means controlled by said'polarized relay and including saidcircuit controlling con.- tactinitsnormally closed position forcontrollingsaid. poweroperating means tooperate the switch to a positionof correspondence with said polarized. relay, and means controlled bysaid neutral relay when energizedfand effective when and 'only'whenxsaidselector is in its said onepositionfo-r restoring: said circuitcontrolling contact to its. normally closed: position. v

. 7.. The combinationwith a railway track switch h'avinga two-position:-selector' effective in but oneposition to condition the switch for poweroperation,v ofa circuit controllingcontact opera tively associated with.the selector and operated from. a-normally closed position to an openposition when the selector is moved out of its said one position, saidcontact having means for maintaining the contact in its open positionwhen said selector is restored to its said one position, a switchcontrol lever, a polarized switch control relay, means controlled bysaid lever and efiec- 'tive when and only when said selector is. in itsto operate the switch. to-a position of correspond-' ence with saidrelay, and means controlled by said. switch control lever and effectivewhen and only when said selector is in its said one position and saidlever is out of correspondence with said relay for restoring saidcircuit controlling contact to its normal position.

8. The combination with a railway track switch.

having a two-position selector effective in but one position tocondition the switch for power operation, of a circuit controllingcontact operatively associated with the selector and operated from anormally closed position to an open position when the selector is movedout of its said one position, said contact having means for maintainingthe contact in its open position when said selector; is restored to itssaid one position, a switch control lever having normal and reversepositions, a polarized switch control relay, circuit means controlled bysaid lever and effective when and only when said selector is in its saidone position for operating said relay to a position of correspondencewith said lever, power operating means for operating the switch, meanscontrolled by said relay and including said circuit controlling contactin its normally closed position for controlling said power operatingmeans to operate the switch to a position of correspondence with saidrelay, and electromagnetic means controlled by said lever when and onlywhen said lever is out of correspondence with said relay and saidselector is in its said one position for restoring said circuitcontrolling contact to its normally closed position.

9. The combination with a railway track switch having a two-positionselector effective in but one position to condition the switch for poweroperation, of a circuit controlling contact operatively associated withthe selector and operated from a normally closed position to an openposition when the selector is moved out of its said one position, saidcontact having means for maintaining the contact in its open positionwhen said selector is restored to its said one position, a switchcontrol lever having normal and reverse positions, a neutral relay, apolarized relay mechanically interlocked with said neutral relay in suchmanner that said polarized relay can operate its polar contacts onlywhen said neutral relay is energized, means controlled by said lever forenergizing said neutral relay when and only when said lever is out ofcorrespondence with said polarized relay, means also controlled by saidlever and effective when said neutral relay is energized provided thatsaid selector is in its said one position for causing said polarizedrelay to operate to a position of correspondence with said lever, poweroperating means for operating said switch, means controlled by saidpolarized relay and including said circuit controlling contact in itsnormally closed position for controlling said power operating means tooperate said switch to a position of correspondence with said polarizedrelay, and means controlled by said neutral relay and effective when andonly when said selector is in its said one position for restoring saidcircuit controlling contact to its normally closed position.

10. The combination with a railway track switch having a two-positionselector eiiective in but one position to condition the switch for poweroperation, of a circuit controlling contact operatively associated withthe selector and operated from a normally closed position to an openposition when the selector is moved out of its said one position, saidcontact having means for maintaining the contact in its open positionwhen said selector is restored to its said one position, a switchcontrol lever having normal and reverse positions, a neutral relay, apolarized relay mechanically interlocked with said neutral relay in suchmanner that said polarized relay can operate its polar contacts onlywhen said neutral relay is energized, means controlled by said lever forenergizing said neutral relay when and only when said lever is out ofcorrespondence with said polarized relay, other means also controlled bysaid lever and effective when said neutral relay is energized forcausing said polarized relay to operate to a position of correspondencewith said lever, means controlled by said selector lever in the other ofits two positions and interposed in said other means for preventingoperation of said polarized relay when said selector is in its saidother position, power operating means for operating said switch, meanscontrolled by said polarized relay and including said circuitcontrolling contact in its normally closed position for controlling saidpower operating means to operate said switch to a position ofcorrespondence with said polarized relay, and means controlled by saidneutral relay and efiective when and only when saidselector is in itssaid one position for restoring said circuit controlling contact to itsnormally closed position.

CLARENCE W. DALZELL.

